Extended Finite Element Method

Appendix B

J Integration

The field of fracture mechanics is concerned with the quantitative description of the mechanical state of a deformable body containing a crack or cracks, with a view toward characterizing and measuring the material resistance to crack propagation. The fracture of materials is mainly divided into two branches: brittle fracture and ductile fracture. For example, cast iron, super-steel, stiff aluminum, titanium alloy, organic glass, and epoxy are all brittle materials. However, the vast majority of metallic materials have a middle or lower stiffness, which experiences a large and plastic deformation at the crack tip location before rupture that cannot be ignored. It is no longer appropriate to use linear elastic fracture mechanics. ...